Best method to synchronize data from an eCommerce platform

I have been assigned to design a high level architecture for an plugin, aimed at fetching and syncing product data from an open source eCommerce platform.

The eCommerce platform allows development of custom modules, with access to complete product catalog. At the same time, the end point, where all data should be received and tracked, has a scheduler assigned to fetch data via SOAP/REST.

During installation of plugin, I need to send complete catalog to the endpoint, which I am thinking to execute through post installation trigger, allowing the endpoint to start syncing process via Web service calls.

Of course, I am avoiding any usage of CRON jobs as we need minimal infrastructure based setup.

Besides, the eCommerce platform has pre-defined and ability to create custom Hooks, which are basically actions (like change in Catalog, new Order), allowing actions to be performed, based on the hook triggers. Using them, I can leverage update requests based on hook/data type. I ll just need to call API for updating catalog based changes according to the hook.

All this seems pretty simple and involves careful inclusion of methods for calling post hook web requests. Is this approach efficient ? There could be millions of data changes happening over, which would trigger multiple hooks. Shall I add these web requests to stack or create bulk requests ? What could be the best way to sync data through web requests if not this way ?